Brake system



1944. J. w. TEKER I 2,355,484

BRAKE SYSTEM Filed April 16, 1945 Inventor: John W Taker His Attorney.

Patented Aug. 8, 1944 BRAKE SYSTEM John W. Teker, Wesleyville, Pa.,assignor to General Electric Company, a corporation, of New YorkApplication April 16, 1943, Serial No. 483,259

4 Claims.

My invention relates to brake systems and more particularly toelectrically operated brakes for vehicles.

An object of my invention is to provide an improved brake system.

Another object of my invention is to provide an improved brake systemutilizing an electrically operated inductor type brake in which therotatable member is formed as a cooling fluid impeller for circulatingcooling fluid through a heat exchanger to dissipate the braking energydeveloped by the brake.

Further objects and advantages of my invention will become apparent andmy invention will be better understood from the following descrip tionreferring to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming part of this specification.

The drawing is a partial sectional view illus trating a brake systemprovided with an embodiment of my invention.

Referring to the drawing, I have shown my invention applied to'a railwayvehicle axle I adapted to be supported by wheels I I. The brake systemincludes an electrically operated brake provided with a stationarymember formed of a pair of axially spaced apart frames I2 and I3 mountedby bearings-I4 on the axle III, which is rotatable relative thereto. Inthe illustrated arrangement, a pair of similar brakes are mounted on theaxle to provide the desired braking force with a minimum diameter forthe equipment. The frames I2 and I3 are formed of magnetic material andeach is provided with a plurality of pole pieces I5 arranged incircumferentially spaced apart relationship and adapted to be excited byan exciting winding I6 arranged to be energized by any suitable sourceof electrical power supply I'I. These frames I2 and I3 are securedtogether in any suitable manner, as by a plurality of bolts I8 and areformed to provide a cooling fluid housing I9 about a centrally arrangedrotatable brake member 20. The rotatable member 20 of the brake isformed of magnetic material and is provided with an annular outer rim 2|having substantially flat side faces adjacent the pole pieces I5 inwhich electric currents are adapted to be induced. The rotatableinduction member 20 may be of any suitable type in which currents areinduced and flow through the effectively short-circuited electricallyconductive portion of this member adjacent the pole pieces I5. In theillustrated construction, this current carrying portion is a unitaryelement, although any other suitable current carrying shortcircuitedmember may be used. This provides an electrically inductive member inwhich a braking torque is developed by electric currents when theexciting winding I6 is energized by being connected to a source ofelectrical power supply I! through a switch 22. of the brakes aremounted on a shaft 23 onopposite sides of a gear 24 which is arranged inengagement with a driving gear 25 secured to the car axle I 0. Asuitable seal is provided about the shaft 23 between the gear box aboutthe gears 24 and 25 and the cooling fluid housing I9 to prevent mixtureof the cooling fluid and lubricant in the gear casing. Each rotatablebrake member is formed as a fluid impeller with outwardly extendingpassages 26 therein which expel fluid outwardly of the rotatable memberunder the action of centrifugal force when the rotatable member is inoperation. If the rotatable member is provided with a radial conductorwinding, the conductors can be made of tubular elements through whichcooling fluid can be passed to cool the winding and the rotatablemember. In order to provide for dissipation of the braking energy whichgenerates heat in the rotatable member rim 2|, the braking systemincludes a circulating cooling fluid circuit. This cooling fluid circuitis provided with a heat exchanger 21 which is connected by cooling fluidconduits 28 and 29 to the exhaust and intake sides of the brake suchthat operation of the rotatable member is adapted. to circulate coolingfluid through the heat exchanger 21. This operation of the rotatablemember 20 would tend to impose a braking action on the car axle I0 evenif the exciting windings I B were not energized. In order to preventthis undesirable action, valves 30 are arranged in the conduits 29 toprevent circulation of cooling fluid when the brake winding I6 is notenergized. These valves 30 are adapted to be biased to a closed positionby a suitable biasing element such as a spring 3| and to be operated toan open position as shown in the drawing by an electromagneticallycontrolled armature 32 and coil 33. The coil 33 for each valve 30 isconnected to be energized such that the armature 32 is actuated to theopen valve position when the brake exciting winding I6 is energized, andthe valve 30 is operated to its closed position by the spring 3| whenthe brake exciting winding I6 is deenergized. In the illustrated system,this is obtained by connecting the coils 33 in shunt across the brakewindings I6 and control resist- The rotatable members 20 tatahie member,on deenergization of the brake exciting winding, thus minimizing anypossible load of the brake on the car axle [0 when the brake excitingwindings 16 are deenergized. The braking torque is controllable by theresistors 34 by varying the energization of the windings l6 and,therefore, the excitation of the brakes. In order to increase theefliciency of the system, a ventilating medium impeller 35 is arrangedto circulate ventilating medium through the heat exchanger 21 todissipate the heat of the cooling fluid therein, and this impeller 35 isprovided with an actuating member 36 of any suitable form. In thedrawing, this actuating member is formed as a fluid. turbine arranged tobe operated by circuiation of cooling fluid through the cooling fluidcircuit, This construction provides for a compact and efficientelectrically operated brake system having a relatively simple controlcircuit which can be combined with an air-brake system to reduce brakeshoe and car wheel wear.

While I have illustrated and described a particular embodiment of myinvention, modifications thereof will occur to those skilled in the art.I desire it to be understood, therefore, that my invention is not to belimited to the particular arrangement disclosed, and I intend in theappended claims to cover all modifications which do not depart from thespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of theUnitedStates is:

1. A brake system including an electrically operated brake having arelatively stationary memher with an exciting winding and a rotatableelectrically inductive member formed as a fluid impeller for circulatingcooling fluid through said brake, means for driving said brake rotatablemember, and means including a heat exchanger comieoted to said brakehaving a ventilating me dium impeller adapted to be actuated bycirculation of cooling fluid by said brake rotatable member forcirculating ventilating medium through said heat exchanger for coolingthe cooling fluid circulated by said brake rotatable member.

2. A brake system including an electrically operated brake having arelatively stationary memher with an exciting winding and adapted toconiid and a rctataole electrically iner for providing a braking torqueas a fluid impeller for circulating cooling fluid through said brake,and means in Jchanger connected to said brake having a ventilasingmedium impeller arranged to be operated in response to circulation ofcooling fluid by said brake rotatable member through said heat exchangerfor circulating ventilating medium through said heat exchanger forcooling the cooling fluid.

3. A brake system including an electrically operated brake having arelatively stationary exciting member with an exciting winding and arotatable inductor member formed as a fluid impeller, means including aheat exchanger connected in a fluid circulating circuit with saidrotatable member for cooling a fluid impelled therethrough by saidrotatable member, means responsive to energization of said brakeexciting winding for permitting circulation of fluid through said heatexchanger and said brake rotatable member and for closing offcirculation of fluid through said heat exchanger and said brakerotatable'member on deenergization or said brake exciting winding, andmeans including a ventilating medium impeller adapted to be operated inresponse to circulation of cooling fluid by said brake rotatable memberfor circulating ventilating medium through said heat exchanger todissipate heat generated in said brake rotatable member and transferredto the cooling fluid.

4. A brake system including an electrically operated brake having arelatively stationary exciting member with an exciting winding and arotatable inductor member formed as a fluid impeller, means for drivingsaid rotatable brake member, means including a heat exchanger connectedin a fluid circulating circuit with said rotatable member for cooling afluid impelled therethrough by said rotatable member, means including avalve operated in response to energization of said brake excitingwinding for permitting circulation of fluid through said heat exchangerand said brake rotatable member and for closing ofl! circulation offluid through said heat exchanger and said brake rotatable member ondeenergization of said brake exciting winding, and means including aventilating medium impeller having an actuating member arranged to beoperated by circulation of fluid through said heat exchanger forcirculating ventilating medium through said heat exchanger to dissipateheat generated in said brake rotatable member and transferred to thecooling fluid.

JOHN W. 'I'EKER.

